Compressible lampholders with recessed contacts for double ended discharge lamps



Aprll 17, 1956 J. M. PISTEY 2,742,521

COMPRESSIB MPHOLDERS WITH RECESSED CONTACTS F0 U LE ENDED DISCHARGE LAMPS Filed Aug. 29, 1955 5 Sheets-Sheet l [0149/7 for:

(/0 7 M P/s/e /fis Affamgg April 17, 1956 2,742,621

. M. PISTEY COMPRESSIBLE LAMPHOLDERS WITH RECESSED CONTACTS FOR DOUBLE ENDED DISCHARGE LAMPS Filed Aug. 29, 1955 5 Sheets-Sheet 2 /943 Affarxggy Apnl 17, 1956 J. M. PISTEY 2,742,621

COMPRESSIBLE LAMPHOLDERS WITH RECESSED CONTACTS FOR DOUBLE ENDED DISCHARGE LAMPS Filed Aug. 29, 1955 s Sheets-Sheet s II IIIII [five/1 for (AM/1. M P/sf W ffii;

14/3 A'fforflgy U w at Pa en I 2,742,621 w COMPRESSIBLE LAMPHOLDERS wrinnucassun CONTACTS-FOR DOUBLEENDED DISCHARGE 'YLAMPS John M. Pistey, Falrfield, Connl 'ns'slgnor'to General Electric, p y, 8 orporation'of'biew York Application August 29, 1955, Serial nafsa pis 9 Claims. (c1. ass- 59) The present invention relates to lampholders for double ended electric discharge lamps of the iluores'cent type hav- H was filed on September 15, 1953, issued as Pa'tentiNo.

2,716,739 on August 30, 1955;a1'1d assigned to the same assignee as is the present invention. The novel lamp base of the Lemmersfa plieation makes possible the utilization. of the usual inlead' wires "of the lamp electrodes as the .lamp terminalsf thus 'elir'nin'ating the need for externally protruding contact pin The inlead wires are recessed within anbutwardly projecting electrically insulating part of the base to protect them from accidental contact. r I v This invention "is likewise related Ito'theapplicants copending application, .Serial No. 452,851, which was filed on August 30, 1954, issued as Patent N10. 716,738 on August 30, 1955, and assigned to thejsaniie assiguee as is the present invention. Fluorescent lamps are supported at each end by a lampholder, and the smaller the size of a lampholder from its lamp engaging face to back face, the shorter the over-all distance will be between the backs offt'he lampholders. Thus, i 1 i ising-th compactlamp holders embodying my invention, lamp'fixturesforsupporting the lamps may be reduced in sizethereby eifecting a cost saving for the "lamp fixture-m u facturer as wen; as making it possible to ncre sed; illumination by installing more fixtures for a'g'iv' eiling length and reducing dark spotsbetween the lamps.

A set of lampholders embodying my invention comprises a stationary holder and a compressible holder in axial alignment. "The compressible 'lainpholder has a spring-biased retractable ciover' so that one end of the; lamp may be forced into; the holder'bypushing against the cover while the other end of the lamp. may be brought into position in alignment with the opposite stationary lampholder. Hence, wheuthe lamp i'slrele'ase'd it will be compressed between the two lampholders. v

v A feature of thelampholders o'fthis' t ventionis' a, pair of spring-pressed, closely spaced, insulated electrical contracts recessed within the holder having lamp terminal engaging portions which diverge outwardly before a lamp base is inserted in the .holderand which are, moved by the insertion of the lamp base-into thchold'en. .aAs a result of a cam action between the holdencon'tacts and the lamp terminals, each of the contactsjmake's. a wiping electrical contact with a temninal o-f" thelairip. Another advantage is that the spring members and mntactsof the holders are so arranged that the cover with its lamp base-receiving cavity in the front ia'ce'tnay be assembled in either its horizontal orits 'vertica l position- This is a'desirable quality for a lampholderthatis to be used in 'ice . 2 This invention makesit possible to stagger the fastening screws for each of the back-to-back lampholderswhile retaining a particular position of the lamp base-receiving cavity in'the front face of each lampholder so that it is possible to remove a single lampholder and service it without disturbing the position of the other.

The primary object of this invention is to provide a lampholder for tubular lamps having bases with recessed terminals so that the lamps may be mounted by longitudinal motion in the lampholders while the size of each lampholder from frontto back is retained ata minimum dimensionl e g A further object of this invention is to provide lampholders with pivoted contacts which are recessed in the front'face of the holder for receiving the recessed terminals of'a'lamp base. v s I A further object of this invention is to provide a' lampholder with pivoted contacts" which normally diverge outwardly from each other when the lamp is removed from the holder. s A further object of this invention is to provide a fluorescent lampholder with suitable. spring means which may be so positioned that it is possible to select either a horizontal'or a vertical position for the lamp base-receiving cavity in the. front face of the holder. Myinv'ention will be better understood from the follow ing description taken in connection with the accompany ing drawings and its scope will be pointed outv in the appended claims. g g Y Figure l is a side elevational view showing the novel lampholders of the present invention and a lamphaving bases withrecessed terminals mounted in the holders. Figure 2, is' a view similar to that of Figure l with the lampholdersshown in cross-section; theviewof the left; hand lampholder, being taken on' the lines 2-2.0f. Figure3. Figure 3 is. a front view of' 'th etleft-hand lampholder ofFigureZ. l Figure 4 is a front view of the right-hand lampholder ofFigure 2. i 1 s Figure 5 is an end view of the lamp base which: is tobe mounted i'nthe lampholders embodying this invention; Figure 6 is an explodedview of theIleft-hand lamp; holder of Figure '2. g 1

Figure 7 is an exploded view ofv the right-hand lamp holder of Figure 2. Figure 8 is a cross-sectional view similar to that of the right-hand lampholder of Figure 2 except that the lamp base has been removed from the holder.

Figure 9 is a rear view' of the cover member of Figure 6 with one of the contact" members located therein.

Figure ljOis a cross-sectional: view of a modification of thestationary lampholder of Figure 7. I

Figure 11 is a view similar to Figure 10 showing alamp supported therein." i

. Figure 12 is an exploded. view of the lampholder of V Figure 10.

Referring in detail to the drawing andparticularly to" Figure 1, the lamp has a tubular glass envelope 10 providedwith bases 11 and, 12 attached to its ends, and is supported between a pair of lampholders 13 and 14wh'i'ch are to be attached to a suitable support which may be.

part of a lighting fixture. The compressible holder '13 is shown in cross-section at the left-hand side of Figure '2 as well as in the exploded view of Figure 6,.while the stationary holder 14 is shown in cross-section at the righthand side of Figure 2 and in the exploded view of Figure 7. The par-ts which comprise the holder 13 may be best explainedwith reterence to Figure 6 which shows a recessed'base member 16 of suitable molded insulating material having an open end 17 for receiving an insulating cover 13 that is adapted to-move 'back -and forth in' the base. Four equally spaced notches 19 are located around the periphery of the cover to mate with four similar guide ribs 20 on the interior'of the side walls of the base. A metal cup 21 fits over the main portion of the base 16 andis fastened therewith when the lanced tangs 22 spring into the slots 23 of the base in a well-known manner. An outer flange 24 of the cup serves as a limit means to prevent the cover 18 from becoming separated from the base.

The front face of the cover 18 has a non-circular cavity 25 for receiving the lamp base 11 of Figure 5. A central projection 26 is located in the cavity with a pair of opposite groves 27 formed therein. A pair of contacts 30 are located behind the cover 18 and they each comprise a lamp terminal-engaging portion 31, a pair of spring seats 32 and a pair of fulcrums 33. Looking at Figure 9 which is a back view of the cover 18, there is shown a pair of depressions 35 each having an opening 36 through which the terminal engaging portion 31 of the contact extends. The fulcrums 33 are located adjacent the side of the cover while the coil springs 37 bear against the bottom wall of the base and the spring seats. 32. The portion.3 1 of the contact is guided in the groove 27 of the projection 26 of the cover as well as being insulated from the other such portion. Because of the relative positions of the fulcrums 33 and the portions 31 of the contact, the springs 37 normally pivot the contacts slightly away from the projection 26 when the lamp base is removed. Thus, when the lamp is being assembled in the holder, the recessed terminals of the lamp base will wipe against the portions 31 of the contacts to make good electrical connection therebetween. The symmetry of the four coil springs 37 in the base 16 make it possible to adjust the position of the cover 18'so that the cavity 25 may be in either its horizontal or its vertical position. A lead wire 38 having a ring type termirial 39 may be inserted through an opening (not shown) in the back of the base and fitted over the spring seat 40 therein of one of the springs of each related pair of springs 37 so that the holder may be connected as part of an electrical circuit. The back of the base 16 has a pair of mounting holes 41 for receiving fastening screws (not shown) so that the holder may be attached to a supporting surface.

The lamp bases 11 and 12 are identical so that reference will be made to only base 11 of Figures 2 and 5. This base comprises an annular metal shell 42 and a disk 43 of electrically insulating material, such as an organic plastic. The inner rim of the shell 42 is imbedded in the periphery of the disk 43 to mechanically join these elements together as shown in Figure 2. The base 11 is secured to the end of the glass envelope 10 by a body of basing cement 44. The disk 43 has an oval-shaped embossment 45 which is to be fitted in the cavity 25 in the front face of the cover 18. A passage 46 extends completely through the disk so that the wire inleads 47 and 48 connected to electrode 49 of the lamp may be brought outwardly to constitute recessed electric terminals for the lamp. Thus, both the contacts 30 of the lampholder 13 and the terminals 47 and 48 of the lamp bases 11 and 12 are recessed so that they may not be touched accidentally in the ordinary handling of the lamp incident to its insertion and removal as described above.

' The stationary lampholder 14 of Figures 2, 7 and 8 the cover with the short leg 62 of the contact guided in the "groove'55 in 'the" projection 54. As shown in Figure 8,

the contacts 56 diverge outwardly from the projection 54 when the lamp is removed so that there is a double wiping action between the holder contacts and the lamp terminals.

The base 50 is of unique design in that the parallel springs 57 may be located in either a horizontal or vertical position. i This arrangement is afforded by the symmetry of the group of four partitions 63 and the central squareshaped depression 64. The mid-portion of each spring 57 is adapted -to be seated in the depression 64 adjacent the side wall; -The.lead wire 65 has a U-shaped terminal 66 that supports one end of the spring 57. Three notches 67 are made in the sides of the base so that the pair of lead wires of the hplder may. be shifted to accommodate the different positions of the springs 57. The terminals 66 are seated in the base so that their top surfaces are flush with a related supporting surface for the opposite end of the spring. The partitions 63 each contain a threaded opening 68. so that the cover 51 may be fastened in either its horizontal or vertical position.

In the modification of the stationary lampholder 70 of Figures 10-12, a'major change has been made by substituting a pair of contacts 71 of strip material which have an integral spring portion 72 for giving double wiping action, as well as a locating ring 73 and a terminal end 74 so that a bare lead wire may be crimped thereto. In Figure 12 the holder 70 is shown as comprising a recessed base 75 and a co'ver 76 assembled therewith by suitable screw means 77105 Figure 12. The cover 76 is substantially the-same as'pover 51 of Figure 7, except that the opening78 for receiving the contact 71 is wider. The locating ring 73 fits over the stud 79 in the base and a depression 80 in the base accommodates the terminal end 74 of the contact adjacent the lead wire-receiving opening I 81 in the sidewall of the base.

has a recessed base 50 of molded phenolic or other suite able electrical insulating material and an insulating cover 51-fastened by screw means 52 over the face of the base. The appearance of the cover 51 is similar to that of cover 18 of Figure 6 in that it has an oval-shaped cavity 53 for receiving the embossment 45 of a lamp base. In the cavity 53 is a projection 54 having opposite grooves 55. The L-shaped contacts 56 are each positioned on an elongated spring 57 of strip material having ends 58 which are bent under to form spring feet. The long leg 59 of the contact has a rounded free end 60 which is confined between the base and cover to serve asthe fulcrum for,

thetcontact. Each contact extends through a .slot 61 in The freeend 82 of the spring portion 72 of the contact is slightly bent, as shown in Figures 10 and 11, to receive the rounded projection 83 of the cover which clamps the end 82.to vthe base. When the lamp is removed from the holder, the contacts 71 assume the divergent position shown in Figure 10. Thus, in inserting the lamp in the base the lamp terminals cam ,thercontacts of the lampholder to'ward the central projection of the cover to give a double wiping actionbetween the contacts and terminals. 'It will be readily appreciated by one skilled in this, art that this stationary lampholder has been reduced to the least number of parts, namely, a base and a cover with a'pair of contact members and a pair of fastening screws for holding the parts assembled.

Accordingly, having described my invention of a novel set of lampholders having recessed contacts which are pivotally mounted therein, it will be readily apparent to one skilledin this art that I have been able to reduce the depth of these lampholders to a minimum practical dimension. I have likewise made it possible to assemble the coversv of the modifications shown in Figures l-9 in either 'a horizontal or 'a vertical position with respect to the front face ofthe base. While in the modification of Figures 10-.12 of a stationary lampholder I have reduced the number of parts to an absolute minimum because each' contact has an integral spring portion, locating ring and term'inal' end.

"Modifications of this invention will occur to those skilled in this art and it is-to be understood, therefore, that this invention is not limited to the particular embodiments clisclosed'but. that it is intended to cover all modifications which are within the true spirit and scope of i this invention.

and a pair of pivotally mounted contact members located in the housing, each contact fulcrumed adjacent the side of the housing and extending through an opening in the cover to lie within a common plane on opposite sides of the said projection, and spring means in the base for forcing the inner ends of the contacts to pivot away from the projection so that they normally diverge outwardly when the lamp is removed.

2. A lampholder comprising a hollow housing having a recessed base and a cover member, a non-circular cavity in the outer face of the cover for receiving a lamp base, and a central projection within the cavity having a pair of grooves on its opposite sides, a pair of pivotally mounted contact members located within the housing, each fulcrumed adjacent the side of the housing and extending through an opening inthe cover to lie within the groove.

on the side of the projection so that the contacts will be insulated from each other and guided in its movement by the said projection, and spring means in the base which bear against the contacts so that their inner ends are pivoted to a divergent position when the lamp is removed whereby a wiping action is present between the said contacts and the terminals of the lamp base as the lamp is inserted in the holder.

3. A lampholder comprising a hollow housing having a recessed base and a cover member, the cover being guided for reciprocating movement in the base, and abutment means for holding the base and cover assembled, a cavity formed in the front face of the cover for receiving a lamp base, the cavity having a central projection therein with a groove formed on opposite sides of the projection, a pair of contacts located in the housing and extending through openings inthe cover to lie within the grooves of the said projection, the opposite end of each contact being fulcrumed adjacent the side wall of the housing, and a pair of springs for each contact seated on the base and bearing against the underside of the contact at spaced points, the fulcrum point of each contact being below the free end of the contact so that when the lamp base is removed from the holder the free ends of the contacts tend to pivot away from the projection.

4. A lampholder comprising a hollow housing having a recessed base and a cover member fastened thereover, a cavity in the front face of the cover for receiving a lamp base, and a central projection located in the cavity, a pair of L-shaped contacts of strip material in the housing and extending through an opening in the cover with the short legs of the'contacts separated by the projection while the opposite ends of the contacts are fulcrumed away from the center of the housing so that the contacts move in a common plane, a spring member supported on the base and bearing against the mid-section of the long leg of each contact to normally pivot each contact slightly away from the projection, the said springs comprising a member of strip material where the ends are doubled under to serve as the spring portions.

5. A lampholder comprising a hollow housing having a recessed base and a cover member, a cavity in the front face of the cover for receiving a lamp base, and a central projection located in the cavity having a groove formed on its opposite sides, a pair of contacts of strip material positioned in the housing, each contact comprising an onset spring portion having a free end held between the base and cover, a V-shaped contacting portion which extends through the cover and is located in the groove of the said projection, and an integral portion for locating the contact in the base and making connection with a bare lead wire.

6. A lampholder as recited in claim 5 wherein the integral portion comprises a locating ring having a terminal which may be crimped over a bare lead wire.

7. An article of manufacture of a contact of strip material for a fluorescent lampholder comprising an offset spring arm joined with a V-shaped contacting portion and an integral portion of a locating ring with a terminal for making connection with a bare lead wire.

8. A fluorescent lampholder comprising a hollow housing with a cavity in its front face for receiving a lamp base, a central projection Within the cavity, and a pair of pivotally mounted contact members located in the housing, each contact fulcrumed adjacent the side of the housing and extending through an opening within the cavity to lie in a common plane on opposite sides of the said projection, and spring means bearing against the contacts for forcing the adjacent ends of the contacts to pivot away from the projection so that they normally diverge outwardly when the lamp is removed.

9. A lampholder as recited in claim 8 wherein there is a groove on opposite sides of the projection to support I and guide the movement of the adjacent ends of the contacts when they are engaged by a lamp.

References Cited in the file of this patent UNITED STATES PATENTS 1,717,762 Davis June 18, 1929 1,980,187 Crawford Nov. 13, 1934 

